| ZHOU Peng,LIN Nai-ming,TIAN Wei,YAO Xiao-fei,TIAN Lin-hai,TANG Bin.Wear and Corrosion Resistance of Microarc Oxidation Coatings on TC4 Alloy[J],44(11):14-20 |
| Wear and Corrosion Resistance of Microarc Oxidation Coatings on TC4 Alloy |
| Received:July 16, 2015 Revised:November 20, 2015 |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2015.11.003 |
| KeyWord:TC4 alloy microarc oxidation ceramic coating wear resistance corrosion resistance the simulated producing well solution |
| Author | Institution |
| ZHOU Peng |
Taiyuan University of Technology, Taiyuan , China |
| LIN Nai-ming |
Taiyuan University of Technology, Taiyuan , China |
| TIAN Wei |
1. Taiyuan University of Technology, Taiyuan , China; 2. China United Northwest Institute for Engineering & Research, Xi'an , China |
| YAO Xiao-fei |
Xi'an Technological University, Xi'an , China |
| TIAN Lin-hai |
Taiyuan University of Technology, Taiyuan , China |
| TANG Bin |
Taiyuan University of Technology, Taiyuan , China |
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| Abstract: |
| Objective To compare the wear and corrosion resistance of coatings fabricated in different electrolytes, to obtain the electrolyte system producing ceramic coatings with best properties under the experimental conditions. Methods Microarc oxidation (MAO) treatments were conducted on TC4 alloy samples in NaAlO2 , (NaPO3 ) 6 and Na2 SiO3 electrolytes, respectively, with the same electrical parameters and the treatment time was 15 min. Besides, the surface morphology, chemical composition and phase constitutions of the ceramic coatings were analyzed. The wear resistance of the TC4 alloy and the ceramic coatings formed in different electrolytes was compared by friction and wear testing under dry friction condition. By testing polarization curve, the corrosion resistance of TC4 alloy and three ceramic coatings was comparatively analyzed. Results The results showed that the ceramic coatings fabricated in different electrolytes had similar surface morphology, with many small pores and local bulge on the surface, but they were built up by different phase constitutions. The main phases of the coatings fabricated in NaAlO2 , (NaPO3 ) 6 and Na2 SiO3 electrolytes were Al2 TiO5 , AlPO4 , TiO2 , respectively. Compared with the substrate, tribological test revealed that under the load of 10 N against Si3 N4 ball, the mass loss of all the coatings had a significant reduction, among which, the mass loss of coating formed in (NaPO3 ) 6 electrolyte was only 1 / 22 that of the substrate. In the simulated producing well solution, comparing ceramic coatings with TC4 alloy, the analysis results of polarization curves showed that the corrosion potential (Ecorr) was obviously changed to positive and the corrosion current (Jcorr) was significantly reduced. The Ecorr and Jcorr values of the coating formed in (NaPO3 ) 6 electrolyte were improved from -0. 311 V to 0. 777 V and reduced from 9. 634×10 -7 A / cm2 to 2. 595×10 -8 A / cm2 , respectively. Conclusion MAO treatments could significantly improve the wear and corrosion resistance of TC4 alloy, and the coating prepared in ( NaPO3 ) 6 electrolyte had relatively good comprehensive performance, with the potential of meeting the requirements for application of TC4 alloy in oilfield environment. |
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